Our Logo600se flies on 710mm blades at 1500-1600 rpm at 18lbs/8kg. I've flown in temps well below 0F/-20C. I was worried about the plastic getting brittle but I haven't experienced any problems yet.

As far as optimal payload for blade size, in my humble opinion you want the heli to be at the upper weight limit that you are comfortable auto-rotating. The heavier the disc loading the better the heli handles turbulence.

As far as optimal payload for blade size, in my humble opinion you want the heli to be at the upper weight limit that you are comfortable auto-rotating. The heavier the disc loading the better the heli handles turbulence.

+1.

Smaller blades CAN carry good payloads, but they will auto like a cement truck...

Our Logo600se flies on 710mm blades at 1500-1600 rpm at 18lbs/8kg. I've flown in temps well below 0F/-20C. I was worried about the plastic getting brittle but I haven't experienced any problems yet.

As far as optimal payload for blade size, in my humble opinion you want the heli to be at the upper weight limit that you are comfortable auto-rotating. The heavier the disc loading the better the heli handles turbulence.

Just remember there are a lot of factors when considering auto rotations. In full size helicopters there is something called a "dead man's curve", it's basically a curve on a height/speed graph where if you are below the curve, then you won't have the energy to do an auto rotation. Basically the slower you are flying, the higher you need to be; and the lower you are flying, the faster you need to go in order to successfully auto rotate. Weight and disc loading are huge factors in this graph.

As we increase the weights of these A/P machines we are starting to see more full scale behavior (more so then even "scale" r/c helis). Dead man's curve and transitional lift are really important to understand for a successful auto rotation or just successful flight on a heavy A/P machine. For example coming out of a steep decent with a very heavily loaded helicopter is not as easy to do, you need to carry speed and fly it out of the dive more like an airplane, similar to what a full size helicopter will do.

When you fly a heavy A/P machine you may at first think, wow this feels really heavy, but that is because you are still flying it like a normal model helicopter. When you start flying it like a full size helicopter you will be amazed at how much weight you can really carry and still have a good margin of control.